Mixing apparatus



Sept. 29, 1931. w. G. BURNS ET AL MIXING APPARATUS Filed April 12 1928 5Sheets-Sheet l INVENTOR. WILLIAM G. BURNS ARCHIBALD D. KIRKLAND ATTORNEYSept. 29, 1931.

W. G. BURNS ETAL MIXING APPARATUS Filed April 12, 1928 5 Sheets-Sheet 21 IN VEN TOR.

- I WILLIAM G. BURNS ARCHIBALD D KIRKLAND I BY ' A TTORNEY Sept. 29,1931. w. G. BURNS ET AL MIXIING APPARATUS Filed April 12, 1928 3Sheets-Sheet 3 ATTORNEY facturer rinds Patented Sept. 29, 1931 UNITEDSTATES WILLIAM G. BURNS AND ABCEIBALD D. IIRKIJAHD, 0] JABIZ BURNS d7SONS, INC., 0] NEW YORK, N. Y.,

A CORPORATION 0] NEW YORK mme APPARATUS Application fled April 18,

This invention relates to apparatus for mixing comminuted materials suchas ground coffee-"and chafl'.

' By the ordina" practice, the cofi'w manu tiie coffee and either leavesthe chaff t erein in large flakes which is obj ectionable to someclasses of customers, or removes the chaff and stores it either to sellor throw away. If separated chafi is ground to a degree of finenessapproximating that of the cut or ground coffee or to a finer degree andthen mixed therewith in the natural proportion occurring in the bean,the mixture is not only homogeneous and non-stratifying, 16 but hasadvantages giving improved cup qualities when infused.

The principal object of this invention is to provlde a simple, compactapparatus for I thoroughly mixing materlals such as ground coffee andchafl' in the desired proportions.

The apparatus is adapted to be used 1n direct association with standardapparatus for granulating coffee and separating the chaif therefrom, andmay have a chafl' grinder connected directly thereto.

The invention comprises a mixing drum which is provided with meanswhereby a predetermined reserve amount of mixed material is constantlykept in the mixer, the material being mixed back and forth therein andcontinually overflowing through an elevated discharge at one end. Bythis apparatus the coffee manufacturer avoids the necessity ofseparately storing the coffee and the chaff and by attaching thiscompact apparatus to his cofiee grinder, or granulator, can achieve asubstantially full automatic operation on the coffee from the coffeebean to the final proper mixture of ground coffee and chafi which can beeither bagged, canned or stored in bins.

Ground coffee and chaff are fed into the same end of the drum and themixture is then moved back and forth by spirally disposed mixing blades,some of which move it in one direction and others in the opposite. Thosetending to move it from the discharge end toward the inlet end arespaced from the wall of the drum and are preferably greater in number soas to tend to move the material 1828. Serial Io. 2,7.

more toward the inlet than the dischar e end. As the material is thusmoved back an forth and tumbled around and since a definite quant1ty iskept in the drum all the time, due to the elevated discharge opening, athorough mixture is insured.

The invention is illustrated in the drawings of which,

Fig. 1 is a side elevation, partly in section, of the apparatus;

Fig. 2 is a vertical transverse section tlrii ughl the apparatus takenon the line 2-2 0 1g.

Fig. 3 is a transverse section through the mixing device taken on theline 3-3 of Fig. 1

Fig. 4 is a partial longitudinal section through the lower end of themixer showing the arrangement of discharge gates;

Fig. 5 is a section taken on the line 55 of Fig. 6 showing a modifiedform of discharge gate;

Fig. 6 is a partial end elevation of the discharge gate shown in Fig. 5;

Fig. 7 is a partial end elevation of the mixer showing a still furthermodification of a discharge gate and operating device therefor;

Fig. 8 is a side view of the form of gate shown in Fig. 7.

The preferred form of the invention, as illustrated in the drawings,comprises the combination of a separator A, a inder B, and a mixer C.The separator is o the usual conical centrifugal type having a materialinlet pipe 10, an air discharge pipe 11 and a conical casing 12 taperingin an inverse manner toward a bottom opening through which the materialdischarges. The bottom of the separator is provided with an outwardlyextending flange 13 which is disposed between the top of the casing ofgrinder B and a ring 14. The ring 14 is sufliciently loose so that theseparator can be rotated to dispose the inlet pipe 10 in any-desiredposition with relation to the rest of the ap aratus.

Fastened to the ring 14 1s a bar 15 which ex tends radially inwardacross the discharge opening of the separator A. This bar has anaperture to receive a bent rod 16 on the lower end of a square bar 17.This bar extends upwardly along the curved wall of the separator NEWYORK, N. Y, ABSIGNOBB TO and has at its upper end a roller 18. Near itsower end, bar 17 is provided with a cross bar or wire 17a. The bar 17,due to the whirling action of the air and material in the centrifugalseparator A, is rotated around the casing, the roller18 traveling on thewall of the separator. This causes a rotary motion of the bar which incon 'unction with the bent rod 16 and cross bar 1 a, will cause astirring action in the material in the top of the grinder B and thebottom of the separator A so that the chaff will not become clogged inthe apparatus. The grinder B comprises a rectangular casing in which ashaft 1712 is longitudinally mounted. This shaft carries a pulley 18a atone end, connected by a belt 19 to a pulley 20, mounted on a shaft 21extending across the inlet end of the machine. The shaft 17d is providedat each end within the grinder casing with spider frames 22 and 23, suporting as shown four longitudinally exten ing brush bars 24. These brushbars are rovided with brush bristles 25 which are of airly heavymaterial. The brush shaft 17 d rotates in the direction of the arrowshown in Fig. 1 and the brushes in rotating sweep over the u per surfaceof a screen 26 which is arrange in the inder casing in the form of'atrough. This screen is preferably of quite'a fine mesh, such as a 40 or45 mesh, and is supported from the upper edge of an open screen frame 27of the same dimensions as the interior of the grinder casing and restingon the bottom thereof. This frame is rovi ed with transverselyextendingcross ars 28, as shown in Fig. 2, which support the bottom of the screen26. As the brushes rotate and brush with considerable force across the'screen they are bent backward and to reinforce them and prevent theirbeing bent too far-backward, there is provided on each brush bar 24 abacking plate such as 29 extending longitudinally across the bar and upa substantial distance along the back of each brush.

In order to adjust the screen supporting frame vertically so as to varythe pressure with which the brushes bear against the screen 26, weprovide bars 30 at each side of the mixer casing C adjacent the grindercasing B and pivoted to the mixer casing beneath the top. The forwardend of these bars are provided with pins 31 which bear against the alower face of the end cross bars 28 of the screen frame 27. The otherend of each bar 30 is engaged by the lower end of a threaded stem 32which extends through an opening in the top of the mixer casing and isprovided on its upper end with a hand wheel 33 to rotate the stem andmove it upward or downward in contact with the bar 30. The lock nutwheel 34 is provided to hold the stem in any adjusted position. By thismeans the screen frame can be raised or lowered and the pressure of thebrushes on the screen adjusted as desired.

The bottom of the grinder casing B opens into the top of the mixer C atone end thereof. Adjacent this end of the mixer casing C, we provide twoinlet pipes 35 and 36 for ground material, such as ground or granulatedcoffee, one inlet on each side. Two inlets are thus provided so that ifthe machine has to belocated where one side is not accessible, the otherside will be accessible for the introduction of material to be mixedwith the ground material dropping from the grinder casing B.Longitudinally and centrally of the mixer casing C is a shaft 37supported at each end in bearings 38 and 39 and havin at the inlet end,outside the casing C, a evel gear 40 meshing with a bevel pinion 41mounted on shaft 21. One end of shaft 21 is provided with a pulley 42from which a belt 43 extends forwardly to a suit able source of power,not shown, such as a small motor which may be mounted on the frame ofthe apparatus. The gear 40, pinion 41 and shaft 21 are coveredsubstantially entirely by a guard casing 44.

. At each end and at intervals throughout its length on the shaft 37 aremounted cross bars 45 forming supports for spirally disposed mixingblades 46, 47 and 48. The blade 46, as shown particularly in Fig. 3, isprovided with a flange 49 of flexible material such as leather whichextends beyond the outer peri hery of the blade and brushes the innersur ace of the mixer casing C. This blade is arranged in such spiralfashion as to convey the material within the mixer from the inlet to thedischarge end from right to left in Fig. 1. The blades 47 and 48 are ofopposite pitch and move the material in the opposite direction. Theselast two blades are spaced a definite distance away from the walls ofthe casing C so that they do not come in contact with the material lyingimmediately along the bottom of the mixer. The casing is provided onthis upper portion with a pivoted cover 50 whereby the interior of themixer may be observed from time to time.

Near the discharge end of the mixer C at the bottom at one side thereofwe provide a discharge opening 51 connected to a pipe 52 leading to afunnel-shaped collector pipe 53. With the discharge opening 51 isassociated a slidable gate 54 connected to a rack 55 with which thepinion 56 meshes. This pinion is mounted on a shaft 57 operated byhand-wheel 58 at one side of the mixer near the discharge end. Thisenables the size of this bottom discharge opening to be varied at will.

We provide another discharge opening 59 in the wall of the mixer at oneside thereof, a suitable distance above the bottom of the m r. hiopening is connected to a pipe 60 having a pivoted cover 61 and leadingto the funnel-shaped collector pipe 53. In

the modification s own in Figs. 5 and 6, this opening 59 can be variedby a slidable gate 5 62, operated by a threaded bar 63 mounted in thebracket plate 64 connected to the outside of the wal of the mixer. Thisadjustment permits the lower level of the elevated dischar e opening 59'to be ad'usted at will. A still urther modification the construction ofthe apparatus for discharging material is shown in Figs. 7 and 8. Inthis form there is no bottom opening, such as 54 (see Fig. 4) but thewall at one side at the bottom thereof is broken away and against it isplaced a plate 65 provided with brackets 66 mounted on a cross bar 67,the ends of which are supported in adjacent brackets 68. This plate as,normal opening 69 near the top thereof which corresponds to the opening59, as shown in Fig. 4. Normally this plate is in the position shown inFig. 8 closing the openin in the wall of the mixer.

e provide means, however, for opening this gate quickl and fully, whendesired, in the orm of a bar 70, pivoted at 71 to the lower rtion of theplate or gate 65, having a handle: 72 at its outer end. Laterallyextendingfrom the bar70 is a lug 73 having an outwardly extending pin 74 thereon. This pin is adapted to ride along the upper surface of a camplate 75, fastened to a bracket 76, dis osed against the outer face ofthe wall 0 the mixer adjacent the gate 65 in its closed position, asshown in Fig. 8. By lifting the handle 72, the pin 74 can be removedfrom the notch 77 and the gate 65 moved to an upper position as'shown indotted lines in Flg. 8.

In the operation of the device, chaff and some fine coffee is drawnoverby the suction created through the'pipe 10 and drops into the se aratorcasing 12, flowing downwardly into e grinder casing B where it isbrushed between the brushes 25 and the screen 26 until it is gradual]broken up into pieces fine enou h to pass through the screen. During therushing action it becomes thoroughly coated with the fine cofi'ee andachieves the same color as the coffee. The determined fineness of thescreen and the coating of the shafl' will insure that when it is mixedwith the granulated cofiee it will not be readily apparent therein. Asthe chaff and anu ated cofl'ee are fed into the mixing 11m they arefirst fed toward the dischar en by means of the outer blade 46. As t ematerial accumulates in the drum, it is engaged by the blades 47 and 48spaced from the wall of the drum and moved in the opposite direction.These latter blades being greater in number than the former, will causethe mass of material to be moved more toward the inlet end than thedischarge end. This tendency will therefore prevent material fromflowing out at the discharge end until it is thoroughl mixed. As theresultant material in t e trough of the drum reaches the lower level ofthe discharge openin 59, it commences to flow out at a rate equa to theinlet flow. By adjusting the height of the gate 62 the amount ofretained material in the trough of the drum can be regulated.

We claim:

1. An apparatus for continuously mixing finely divided dry materialssuch as coffee and chaff, comprising a drum of substantial lengthproviding for the accumulation of an appreciable amount of materialtherein, means for supplying the materials to be mixed at one end of thedrum, there being a discharge outlet at the opposite end of the drum atan elevation above the bottom thereof so that there must be anaccumulation of materials bein mixed within the drum before the mixematerials can pass through said discharge outlet, conveying andagitating devices in said drum constructed to move the material moretoward the inlet end than the outlet end so as to form a greateraccumulation of material at the inlet end than at the outlet end of thedrum, whereby the incoming materials are thorough] agitated and mixedwith previously accumu ated material before being passed through thedischarge outlet.

2. Apparatus as claimed in claim 1 wherein the conveying and agitatingdevices con stitute a plurality of sets of spiral mixing blades, one setof blades being arranged to contact with the inner wall of the drum andfeed the material toward the outlet end and the other set of bladesbeing spaced from the drum wall and arranged to feed the material towardthe inlet end, there being more blades in the latter set than in theformer.

WILLIAM G. BURNS. ARCHIBALD D. KIRKLAND.

